The embodiments described herein relate generally to decontaminating delivered items and more specifically to systems and methods for decontaminating mail during a relatively long period of time in a mailbox.
Anthrax spores have been detected on mail pieces, mail-handling equipment and in or near areas where certain mail pieces that likely contained anthrax were handled. Several people that were in such areas have contracted anthrax disease. These attacks pose a danger of infection that may be lethal to those in affected areas. Additionally, there is no warning system available to provide an early warning that a mail piece contains anthrax spores. Certain members of the general population may fear receiving and handling mail due to the threat of mail terrorism.
Anthrax is a biological agent that has apparently been placed in the U.S. postal delivery system in mail pieces that were camouflaged as ordinary mail and not properly marked or properly contained as a dangerous biological agent. The person placing such mail in the mail system had the apparent sole purpose of delivering the Anthrax as a biological weapon to kill the immediate victims and terrorize others who use the postal system. The Anthrax has apparently been transported in spore form and in such a small form as to float in the air.
The disease known as Anthrax disease is caused by the bacterium Bacillus anthracis that is known as Anthrax. Anthrax is rod-shaped, and relatively large for a bacterium at 1 to 10 μm in length.
The disease may be manifested as pulmonary anthrax or inhalation anthrax when a sufficient amount of Anthrax is inhaled. Such disease has been known as Woolsorter's Disease because Anthrax has been found in hoofed animals and the fur of such animals. Some people working with the fur have inhaled Anthrax.
The disease may be manifested as intestinal anthrax. Intestinal anthrax typically occurs when a person ingests undercooked infected meat. The disease may be manifested as cutaneous anthrax that is typically found when an open wound or sore of a person has been exposed to Anthrax.
Anthrax is a spore-forming bacterium such that it forms tough-shelled capsules known as spores that help it survive unfavorable conditions. The spores are a dormant form of the bacterium that can survive harsher conditions than the active bacterium and may survive in soil for many years. The spores may withstand a lack of moisture, certain amounts of radiation and some disinfectants. The spores may also survive in hotter or colder environments than the active bacterium.
If spores are introduced into a sufficiently warm and moist environment, such as inside a human body, they will then germinate and multiply. The typical hosts for Anthrax are animals, especially hoofed animals like cattle, sheep, goats and horses. Vaccination against Anthrax is not common except for those who are more likely to come in contact with it such as veterinarians and tannery workers.
Decontamination systems and methods have been used for water treatment, food sterilization and medical sterilization. Chlorine gas and chlorine dioxide gas have been used to disinfect sewage and control odor, but it is a poisonous gas. Chlorine gas is heavier than air and will remain close to the ground. Similarly, Ethylene Oxide is known to destroy anthrax spores.
Food sterilization equipment systems include high-energy heavy electron beam systems using electron accelerators, x-ray irradiation systems and gamma ray irradiation. Cobalt 60 is sometimes utilized as a source of radiation. Additionally, ultraviolet light radiation is sometimes utilized.
Biological and chemical weapon or hazardous material decontamination has been performed using liquid sprays, foams or fogs containing decontamination agents such as the Sandia National Laboratories Decon Formulation available from Modec, Inc. of Denver, Colo. and EnviroFoam Technologies, Inc. of Huntsville Ala. Such decontamination agents may not be effective against all contaminants and may or may not be toxic. Superheated steam is sometimes used in decontamination systems. Additionally, dry heat is also sometimes utilized, but is considered less effective than steam. Furthermore, ozone gas may be utilized in the proper conditions to neutralize anthrax spores.
Food and other decontamination systems require high throughput and fast processing times to be economically viable.